7 - Communication

Question 1

What is predicted when offspring will win parent/offspring conflict?

Answer 1

• Piglets do better
  eg. example with piglets and sow in confined or get-away pens. When piglets are in control, they go for their optimum, when parents are in control, they go for their optimum.

Conflicting selecting pressures on parents and offspring.

Question 2

What’s a signal?

Answer 2

Any adaption whose function is to affect the behaviour of other animals or provide stimulus for other animals

• Doesn’t really address fighting .
• IE. deer can use antlers as weapons (eg. pushing) OR as a signal (eg. showing them off)

Question 3

What are the five components of a signal (in order)?

Answer 3

• Sender
• Signal
  [Transmission]
• Receiver [detection, recognition and meaning]
• Response

Signal gets to the receiver, and the receiver has to make a behavioural decision. There’s processing of the signal at the receiver. Meaning is referring to appropriate content for that receiver.

Question 4

What influence the form of signals?

Answer 4

The environment and mediums that they have to pass through

Eg. sticking tail straight up in open grassland for visual signal vs. tactile/olfactory signals.

Might want something that’s not volatile and won’t spread through environment (eg. scratching certain area) or something that is volatile (eg. spraying wide area)

Question 5

What happens to sound as it passes through an environment?

Answer 5

Attenuation (loss of energy/volume with distance)

• From absorption/spreading
• Worse for higher frequencies

Question 6

Is attenuation worse for higher or lower frequencies? How does bird song demonstrate this?

Answer 6

Higher

Eg. Bee Gees getting soaked up by walls, but not bass.

Bird song is lower frequency in forests or dense environments.

Question 7

How do animals make sure that their signals are detected and recognized? (3)

Answer 7

Conspicuousness
- Eg. having low/high frequencies in call

Repetition

Stereotypy (signal stays relatively constant each time)

Question 8

What is the evolution of signals called? Why?

Answer 8

Ritualization

Because many signals look like rituals (eg. peacock fanning feathers or gazelle hopping)

Question 9

What are some common features to signal evolution?

Answer 9

Like an arms race (opposing selective pressures)

• Senders manipulate receiver behaviour
• Receivers anticipate sender behaviour

Signals are honest (on average)

Question 10

Do signals evolve as cues or responses first?

Answer 10

• Signals start as undetected signals
• When it’s the receiver’s advantage to detect cue, he evolves response
• When signaler then benefits from receiver reception, you get signal specialization

Question 11

What ensures signal reliability?

Answer 11

• If interests coincide, none is needed
• If no reliability, there is manipulation
• If it can’t be faked, index?
• If it’s too costly to fake, it’s a handicap
• If fakes are caught, it signals status

Question 12

What are two factors in the transmission of sound?

Answer 12

• Attenuation (loss of energy from absorption and spreading)
• Degradation (loss of form from reverberation)

Both of these are worse for higher frequency sounds

Question 13

How can songs fit the transmission features of a habitat?

Answer 13

Open environment

• Broad bands
• Fast changes (high frequency)

Dense environments
- Lower frequencies and slow changes

Question 14

What three factors influence detection and recognition once a signal arrives at a receiver?

Answer 14

• Conspicuousness
• Repetition
• Stereotypy